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Rates of Competitive Exclusion by the Argentine Ant in Bermuda
Author(s) -
Crowell Kenneth L.
Publication year - 1968
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1934122
Subject(s) - biological dispersal , ecology , biology , competitive exclusion , competition (biology) , pheidole , habitat , geography , hymenoptera , demography , population , sociology
Since its introduction to Bermuda in 1953, Iridomyrnex humilis has expanded steadily, replacing Pheidole megacephala in all habitats. The basis for this competition was not determined. The dispersal rates of Iridomyrmex from 1953—1966 are analyzed. From 1953 to 1959, Iridomyrmex increased its distribution at the rate of 394 ha. per year. However, radius did not increase linearly, and it is suggested that only those foci within a critical distance of the perimeter can colonize new areas. Moreover, after 1959 there was a decrease in both number of new foci and growth of individual foci. Therefore, while Iridomyrmex and Pheidole have not established an equilibrium, the rate of replacement has slowed markedly.